An important class of explosive compounds are known as nitroaromatics, such as trinitrotoluene (TNT) and dinitrotoluene (DNT). These compounds are electron accepting compounds due to the addition of the function nitro groups. This property can be exploited by using an electron donating compound and detecting an electron transfer reaction between the nitroaromatic and donor compound. This mechanism has been used for years in systems which optically excite a conjugated polymer and sense a quenching of its photoluminescence upon exposure to nitroaromatics. Research and development of explosive sensing technologies is very active driven by new novel device designs and materials. Besides chemical resistive type devices organic electrical devices are a generally unexplored field in the arena of explosives sensing.
Organic photovoltaics are similar to their inorganic counterparts mainly because they both rely on incident energy (photons) to create excited states which then become separated and collected at electrical contacts. Single layer organic photovoltaics have poor efficiencies due to inefficient charge separation, usually resulting in an excited state returning to its ground state. In recent years researchers have developed heterojunction organic photovoltaics which combine electron donating and electron accepting layers, similar to an inorganic PN junction. In this configuration the excited state electron can transfer from the donating compound to the accepting compound and has a better probability of being collected at the cathode due the lower energy level of the accepting compound.